TY - JOUR
T1 - The simplified formula for the calculation of aortic valve area
T2 - Potential inaccuracies in patients with bradycardia or tachycardia
AU - Hillis, L. David
AU - Winniford, Michael D.
PY - 1987/1/1
Y1 - 1987/1/1
N2 - Since the Gorlin equation for calculation of aortic valve area is somewhat complicated, a simplified formula has been introduced in which the cardiac output (in liters/min) is divided by the square root of the peak pressure gradient across the valve (in mmHg), yielding a valve area in cm2. This study was done to examine the reliability of this simplified formula in patients with bradycardia or tachycardia. In 68 patients with aortic stenosis, aortic valve area was calculated with both formulae, and the results were compared with one another. In the 43 individuals whose heart rates were 65 to 100 beats/min, the results of the Gorlin equation and the simplified formula showed excellent agreement (absolute percentage difference, 8 ± 8% [mean ± SD]). In contrast, in the 25 patients whose heart rates were < 65 or > 100 beats/min, the absolute percentage difference between the results of the two formulae was 18 ± 13% (p < 0.001). Although the results of the two equations were especially likely to be disparate in these patients, there was no predictable relationship between them. Thus, in patients with bradycardia or tachycardia, the simplified formula should be utilized with caution and cognizance of its potential inaccuracy.
AB - Since the Gorlin equation for calculation of aortic valve area is somewhat complicated, a simplified formula has been introduced in which the cardiac output (in liters/min) is divided by the square root of the peak pressure gradient across the valve (in mmHg), yielding a valve area in cm2. This study was done to examine the reliability of this simplified formula in patients with bradycardia or tachycardia. In 68 patients with aortic stenosis, aortic valve area was calculated with both formulae, and the results were compared with one another. In the 43 individuals whose heart rates were 65 to 100 beats/min, the results of the Gorlin equation and the simplified formula showed excellent agreement (absolute percentage difference, 8 ± 8% [mean ± SD]). In contrast, in the 25 patients whose heart rates were < 65 or > 100 beats/min, the absolute percentage difference between the results of the two formulae was 18 ± 13% (p < 0.001). Although the results of the two equations were especially likely to be disparate in these patients, there was no predictable relationship between them. Thus, in patients with bradycardia or tachycardia, the simplified formula should be utilized with caution and cognizance of its potential inaccuracy.
KW - aortic stenosis
KW - bradycardia
KW - tachycardia
KW - valve area
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U2 - 10.1002/ccd.1810130503
DO - 10.1002/ccd.1810130503
M3 - Article
C2 - 3664627
AN - SCOPUS:0023405574
VL - 13
SP - 301
EP - 303
JO - Catheterization and Cardiovascular Interventions
JF - Catheterization and Cardiovascular Interventions
SN - 1522-1946
IS - 5
ER -